skipjobe

I am building a 350 LT1. I bought a balanced forged rotating assemble with a 383 crank h-beam rods with standard bore pistons netting 377. I have found that the 2 bolt mains are good to about 500 hp. I am trying to get my 3400# Camaro into the 10's which will take about a 200 shot about 700hp.
I decided after some research that splayed caps would be the solution, I called a couple machine shops referred on this page and the second machinist said you can not use standard size pistons after splayed caps are installed because the cylinder needs to be bored with a torque plate installed. So my problem is that like most is a limited budget the pistons are already balanced and I don't know if I can swap them. I know many of you have been in similar situations, This is my first engine build and I am already a $1000 over budget whats new? let me know what is the least expensive route at this point. PS. The roll cage is leaning on the wall along with the drive shaft loop the trans is in the shop getting beefed up.

bjuice

the cheapest most beefy thing you can do other then the obvious you mentoined above is to:

Stud the bottom end and have you some main cap Girdles machined..basically all the girdle is a 1 inch thick tool steel metal that is machined where it lies flush against your main caps..

the studs you will use will have to be the longer ones to go thru the main caps and the homemade girdle...this will strengthen your mains for an easy 700hp..

now keep in mind that when you stud a bottom end you will need a minimum of a line hone if not a line bore..depending on how distorted your mains are.....the studs have that much tensil strength over regualr bolts..

this is still much cheaper then going the other route...

also i have ran these type girdles on my last 3 small blocks..one made over 1,000 hp (blown)..

hope this helps..maybe someone else will have an idea for you also.

Brian

skipjobe

Thanks Brian I will suggest that solution to the machinest and perhaps I can use the splayed caps I have as the new caps with studs.

cepx111

Brian, I put studs and a main guirdle on my bbc, that I purchased on ebay. I mention this to the machine shop when I had my block decked and bored but they made no mention of me needing to line hone it? what's the reasoning behind it? I installed the crank and torqued the mains and everything is smooth> I just want to be on the safe side so hook me up. Thx charles

billhendren

You would do yourself a favor by taking it apart and align honing it.studs with there fine threads have a higher clamp load against the cap and distort it more as compared to a bolt.I have never seen a block that had studs installed where the mains remained round without an align hone.Bill

bjuice

what Bill said exactley.. 8)

Thanks Brian

cepx111

Thx guys I'll do that.

bjuice

the thing is ..you may get the bearing's and crank to bolt up and even seem like its spinning freely..but whats gonna happen is excessive bearing wear ..and a good chance that heat spots could form on a certain spot on the bearing that is wearing faster and could cause a bearing to spin,,messing up much stuff....

the studs pull the mains down so tight..the mains go from being ROUND to OVAL shape..sometime hard to see by the human eye, but sometime you can see it if you know what your looking for.....but you put a MIC on i and you can see the distortion no problem....the align hone process is fairly simple..some can do it at home with right tools...but if you have to get it done i would say $80 to $150 (high end) would get the job done for you..(standard shop labor)
the biggest thing is getting your motor tore down to that point..if your there already then great...less hassle.
glad we could help.

Brian

cepx111

I'm just starting the assembly process, I haven't even installed the pistons yet. I torqued the crank down and plastigauged the bearings and everything was on target but this was done w/ factory bolts, I've since bought studs and a guirdle. I've got allot of money tied up in this engine so I'm gonna get it checked and make sure its right.
Thx again for the help, Charles

edvancedengines

.

I question this.

I feel that either you mis-understood him or he is wrong. He is corrent in that if you do the splayed caps and torque them down the block will see a different form of stress than it did previously and can distort the cylinders. I can agree with that.

I can agree that it should be then re-honed with caps torqued after finishing and torque plate honed. I can not agree that it should need to be re-bored and re-honed to a different size though. Just re-honing it, should not require new or different sized pistons.

All advice in this thread is good advice in my opinion.

I suggest to keep your 2 bolt caps and to buy and use a main cap girdle on them but to get the align hone checked and re-honed if necessary. You could also just get the 3 center caps repalced to a 4 bolt cap, but I think at the stage you are at the girdle is best bet.

I do not know who has the main cap girdles for the sb chevy now, but I am also getting ready to look for some for one of my similar projects I am on. I heard that Cat is making them, but have not checked yet. Years ago Milidon made them. I know Probe has them for Fords now.

This similar project I am on, has all machine work completed with two bolt caps, and now has a new owner that wants more power from it. lol. I am also looking strongly at figuring something to do with the rear main cap. To me it does not look real strong. I am not sure if anyone is making a billet cap for the rear of these things or not.

Lol . I just answered my own ignorance by going out in the shop and looking. The GM Bow Tie Rear Main Cap is much more beefy.

Ed